Proteomic Landscape and Clinical Implications of Ovarian Carcinosarcoma.

Ovarian carcinosarcoma (OCS) is a rare and aggressive ovarian cancer subtype with poor prognosis and limited treatment options. This study aimed to provide an in-depth proteomic analysis of OCS to uncover molecular features associated with tumor progression, prognosis, and immune microenvironment characteristics. Using mass spectrometry-based proteomic profiling and bioinformatics, we analyzed 14 OCS and nine paired normal ovarian (NO) tissue samples. We identified significant proteomic alterations, including the upregulation of proteins involved in angiogenesis, cell proliferation, DNA repair, and metabolic pathways such as glycolysis. Key signaling pathways, such as VEGF-VEGFR2 and MAPK, were found to be enriched in OCS tissues, pointing to their potential roles in sustaining tumor growth and metastasis. Notably, CAMK family proteins (CAMK2B and CAMK2D) were identified as potential prognostic markers, with high expression levels linked to poor survival outcomes. Immune cell analysis revealed a higher enrichment of mast cells and CD8+ naive T cells in OCS tissues, with mast cells promoting angiogenesis and CD8+ naive T cell presence correlating with improved survival. Additionally, epithelial-mesenchymal transition (EMT) was associated with shorter survival, and high FERMT1 expression was found to be linked to poor prognosis. Weighted gene co-expression network analysis (WGCNA) further identified molecular modules associated with key clinical indicators such as CA125 levels and tumor size, offering novel insights into the molecular mechanisms driving OCS progression. This study enhances our understanding of OCS pathophysiology and highlights the potential of proteomic biomarkers for prognosis and therapeutic strategy development in clinical practice.